应用GC-MS测定葡萄中的5种农药残留

酿酒葡萄是河北昌黎的主要水果种植品种,由于受海洋气候的影响,当地空气湿热,葡萄病害十分严重,因而农药使用十分频繁,为了评价其农药残留水平,我们采用丙酮提取,凝胶分离,硅胶小柱净化,GC-MS的选择离子方式检测对采集的葡萄样品进行5种农药(百菌清、精甲霜灵、苯醚甲环唑、嘧菌酯、高效氯氟氰菊酯)的残留分析.……

Effects of Soil Moisture Content and p H on Residual Dynamics of Chlorothalonil in Acidified Soil

[Objective] This study aimed to investigate the residual dynamics of chlorothalonil in acidified soil under different conditions of soil moisture content and pH. [Method] By simulation tests, the effects of different soil moisture content and pH on chlorothalonil residues in acidified soil were analyzed. [Result] Under different conditions of soil moisture content and pH, the residual quantity of chlorothalonil in acidified soil was reduced gradually with the extension of incubation time. To be specific, the reduction rate of chlorothalonil residues in soil was extremely high within the first three days and slightly declined at 3-7 d; after 7 d, the residual quantity of chlorothalonil in soil was reduced slowly and steadily. [Conclusion] This study provides the reference for soil environmental remediation and maintenance of a health cultivation system.

Degradation of chlorpyrifos alone and in combination with chlorothalonil and their effects on soil microbial populations

In practice, pesticides are usually applied simultaneously or one after another for crop protection, and this type of pesticide application often leads to a combined contamination of pesticide residues in the soil environment. A laboratory study was conducted to investigate the influence of chlorothalonil on chlorpyrifos degradation and its effects on soil bacterial, fungal, and actinomycete populations. Under the experimental conditions here, the half-lives of chlorpyrifos alone, and in combination with chlorothalonil, at the recommended and double dosages, were measured to be 3.24, 2.77, and 2.63 d, respectively. Chlorpyrifos degradation was not significantly altered by its combination with chlorothalonil. However, the inhibitory effect of chlorpyrifos on soil microorganisms was increased by its combination with chlorothalonil, and the increase was related to the levels of chlorothalonil added. Compared to those in the controls, the populations of bacteria, fungi, and actinomycetes were significantly reduced by 44.1%, 61.1%, and 72.8%, respectively, on the first day after treatment （DAT） by chlorpyrifos alone. With the addition of chlorothalonil, the inhibition was increased to 55.2%, 79.3%, and 85,8% at the recommended dosage, and 86.0%, 94.1%, and 90.8% at the double dosage, at one DAT, respectively. The results suggested that combined effects should be taken into account to assess the actual impacts of pesticide applications.

Effects of chlorothalonil and carbendazim on nitrification and denitrification in soils

The effects of chlorothalonil and carbendazim on nitrification and denitrification in six soils in upland and rice paddy environments were investigated. Laboratory aerobic （60% water holding capacity） and anaerobic （flooded） conditions were studied at 25℃ and fungicide addition rates of 5.5 mg/kg A. I. （field rate, FR）, 20 times （20FR） and 40 times （40FR） field rate, respectively. The results indicated that chlorothalonil at the field rate had a slight inhibitory effect on one soil only, and that soil did not nitrify much in the first place. But chlorothalonil at higher rates inhibited nitrification significantly in all soils. For soils JXP and JXU with a pH of less than 5.0, chlorothalonil almost completely stopped their nitrification at 20FR and 40FR during the whole 14 d incubation period. For soils HNP and HNU with a pH of greater than 8.0, chlorothalonil also significantly inhibit nitrification at 20FR and 40FR （p 〈 0.05）. However, NH4＋ that was added to the soil was also almost completely nitrified by the end of the incubation period in these two soils. The effects of chlorothalonil at 20FR and 40FR on the nitrification of JSP and JSU soils, with a pH of 5.4 and 7.2, respectively, were intermediate between the other soil types. Chlorothalonil had no effect on denitrification at the field rate and had little effect at the higher rates of application in some soils. Carbendazim had essentially no effect on nitrification and denitrification in soils assessed.

Synthesis of Novel Benzoylphenylurea Chitin Inhibitors from Chlorothalonil

Twenty-six novel benzoylphenylurea chitin inhibitor derivatives have been synthesized in over 30~50% yield from chlorothalonil 1 via sequential fluorine exchange, aminolysis, hydrolysis, decarboxylation and acylation reactions.

Degradation of chlorothalonil by ultrasonic irradiation:Kinetics and impact factors

Factors on degradation of chlorothalonil(CLT) in water by high frequency ultrasonic irradiation were investigated.The effects of initial concentration of chlorothalonil,dosages of tertiary butyl alcohol,humic acid and initial pH value on degradation of chlorothalonil,as well as the reaction mechanism were studied.The results reveal that chlorothalonil could be effectively degradated by ultrasonic irradiation.The reaction constant value kapp decreased from 0.014 1 to 0.010 2 min-1 with the initial concentration increasing from 50 to 400 μg/L during 180 min irradiation.Tertiary butyl alcohol had negative effect on chlorothalonil degradation,while lower concentration of humic acid promoted the sonolysis,and kapp declined with the further concentration increasing.The kapp varied little when the pH value ranged from 3.10 to 10.28.It may be concluded that mechanical and pyrolysis process played main roles on the degradation of chlorothalonil in ultrasonic irradiation rather than ·OH attack.The electrical energy per order(EEo) values for sonolysis degradation of CLT were also calculated to evaluate the cost of the process.

Synthesis of Novel Benzoylphenylurea Chitin Inhibitors From Chlorothalonil(Ⅱ)

Six novel benzoylphenylurea chitin inhibitor derivatives were synthesized in the yields of 30%_50% from the readily available starting material chlorothalonil 1 viasequential fluorine exchange, aminolysis, hydrolysis and acylation reactions.

Residue Dynamics of Chlorothalonil and Its 4-Hydroxy Metabolite in Scallion

[Objectives] This study was conducted to explore the dissipation dynamics of chlorothalonil （2,4,5,6-tetrachloroisophthalonitrile） in scallion.[Methods] The level of residue and the dissipation of chlorothalonil and its main metabolite 4-hydroxy-2,5,6-trichloroisophthalonitrile in scallion in Beijing and Jiangsu experimental bases were determined via acetonitrile extraction and ultra-performance liquid chromatography coupled with ultraviolet detection （UPLC-UV）.[Results] The dissipation of chlorothalonil in scallion followed the first-order kinetic model and the half-life of chlorothalonil in scallion was 3.5-4.1 d. The final residue of chlorothalonil in scallion decreased over time after the last application. After chlorothalonil was applied at 1 050 or 1 575 g a.i./hm 2 3 or 4 times, the maximum residue level of chlorothalonil was 1.48, 1.21, 0.72 and 0.45 mg/kg 5, 7, 10 and 14 d after the last application, while that of its 4-hydroxy metabolite was 0.25, 0.19, 0.13 and 0.09 mg/kg, respectively.[Conclusions] The results may provide experimental evidence for evaluating the safety of the use of chlorothalonil in scallion.

Synthesis and Fungicidal Activity of Chlorothalonil Derivatives

[Objective]The paper was to develop a novel fungicide with high efficacy and low toxicity.[Method]Chlorothalonil was used as the parent structure,and its 4-position substituent was converted to amino group.Totally 12 amide compounds not reported in the literature were designed and synthesized.Their structures were conformed by 1H NMR.[Result]The preliminary bioassay test showed that compounds JTCN-01,JTCN-05 and JTCN-07 had good control effect on corn rust at the concentration of 200 mg/L,and the control effect of compound JTCN-05 reached 95%.[Conclusion]Some chlorothalonil derivatives had the potential for further development.

Root colonization by mycorrhizal INIFAP^MRin barley seed treated with fungicide

The effect of barley seed treated with chlorothalonil fungicide on mycorrhizal root colonization was evaluated. The treatments were: 1) Seed with Mycorrhizal INIFAP?, one, two and three doses, and uninoculated seed;2) Seed with and without fungicide. Monthly seed plantings were performed with different storage time, looking forward to assessing the colonization degree of the roots. As revealed by the results, the seed treated with chlorothalonil did not lower the root colonization by Mycorrhizal INIFAP?;the chlorothalonil treatment had a 32.63% average root colonization, whereas without chlorothalonil, it was 36.46%. When the seed was treated with root colonization by Mycorrhizal INIFAP?, this was lower in the treatment with one dose;no significant difference was revealed by the treatments with either double or triple doses.?The colonization percentage was progressively decreased by seed storage. The root colonization by Mycorrhizal INIFAP?, throughout the inoculated seed storage time, remained constant and unchanged for the first six months, but then decreased in 50% within a 10-month period for both treated and not treated fungicide seed.

Determination of Residual Chlorothalonil in Textiles

An effective method was established to determine the content of residual chlorothalonil in textiles by gas chromatography/mass spectrometry-selected ion monitoring coupled with ultrasonic extraction technique. Residual chlorothalonil in textiles was ultrasonically extracted using ethyl acetate as the extraction solvent. The extract was condensed and analyzed by gas chromatography/mass spectrometry in selected ion monitoring mode (GC/MS-SIM). The concentration of chlorothalonil was calibrated by the external standard method. Good linearity existed between the peak area and the mass concentration of chlorothalonil in the mass concentration range from 0.2 μg/mL to 42.8 μg/mL. The equation was A = 95,399ρ ? 50,848, with a correlation coefficient of 0.9999. The limit of detection was 0.1 mg/kg for chlorothalonil. The blank samples were spiked at three concentration levels, and the spiked average recoveries changed from 81.9% to 95.4% while the relative standard deviation (RSD) changed from 1.8% to 5.2%. The proposed method was simple, rapid, sensitive and the limit of detection could meet the limit requirements of relevant regulations. Commercially available textiles were measured by this method, and chlorothalonil at different concentration levels was detected in some samples.

A Protocol for Endophyte-­Free Callus Tissue of the Grape Vitis aestivalis “Norton/Cynthiana” (Vitaceae)

Vitis aestivalis is used in commercial wine production. Vegetative propagation of V. aestivalis has shown a low success rate. Although plant tissue culture has been a successful method to propagate many species, V. aestivalis has not yet been reliably grown as pure callus culture due to a fungal endophyte that exists within the plant. This study reports a viable protocol for obtaining fungus-free tissue culture callus from V. aestivalis. Explant tissue was chosen from healthy, actively growing plants grown in a growth room and in a vineyard. Tissues were sterilized with a combination of isopropanol, bleach, and chlorine dioxide gas and plated onto media containing chlorothalonil. The results from this study suggest that in order to obtain endophyte-free callus tissue, vine explants are to be taken from plants grown in a growth chamber simulating springtime conditions, sterilized in a combination of alcohol, bleach, and chlorine dioxide, and plated on selection media containing an antifungal agent, such as chlorothalonil. This technique could potentially be used with plants that have associated endophytes or other contamination problems to establish callus tissue for research and/or commercial propagation efforts.